Bone formation under zinc deficiency conditions was investigated using alveolar implants in guinea pigs, from which bone formed solely during the period of zinc deficiency could be obtained. Thirty-six guinea pigs (GP) weighing 175-195 g were randomly divided into three groups: group 1 received a Zn-deficient (-Zn) diet, (1.0 plus or minus 0.2 ppm Zn), group 2 pair fed control and group 3 ad libitum control. After three weeks of dietary treatment, the right incisor was extracted and a nylon mesh tube (1.0 cm long) was implanted into the incisor alveolar cavity. Two weeks after implantation, all GP were sacrificed, bone containing nylon implants (BCNIs) and femurs were removed for Zn, Ca and P analyses. Compared to the two control groups, -Zn group showed 2- to 4-fold less zinc in femurs and in BCNIs, respectively. Femur, but not BCNI, from pair-fed GP had significantly higher zinc concentration than that of GP in group 3. Ca and P concentrations in -Zn BCNI were not significantly reduced, but P in -Zn femur was. When BCNIs were cultured for 48 hours in BGJ media containing 35SO4 or 14C-glucosamine, -Zn BCNIs incorporated significantly more 14C and slightly higher 35S into their GAG fraction. It is concluded that under our standardized conditions zinc deficiency does not show an effect on Ca and P depositions into bone, but it seems to interfere with glycosaminoglycan metabolism of membranous bone.